Playtest #4 fixes: tile picking, knocked-down state, element gauges, draft timer, live stats, shop items, drones, 赫默, 炎佑, UI flash

- #1 picking by the tile under the pointer (prep, battle, pen, equipment drops); the dragged model stays
  under the pointer (mouse and touch); pixel probe removed; phone ghost-click on the underframe fixed
- #2 two-tap confirm on 机变 cards (like the shop)
- #3 a 同盟 room with one human is untimed like 独立模拟 (no countdown outside battles)
- #4 strategy draft: one synced countdown, 30 s per human turn, timeout takes the highlighted band
- #5 special 维式重锤 (4) and 突变细胞 no longer sold; item card shows where they come from
- #6 operator skill-mode sounds no longer play on normal attacks (纯烬艾雅法拉 and 55 others)
- #7 detail card shows live battle stats and the prep-time battle-start stats (g.unitStats)
- #8 official element gauges on units; burst cooldown (阻回) per PRTS
- #9 knocked-down operators stay on their tile with a redeploy countdown ring
- #10 drone behaviour per PRTS (暴鸰, 先兆者 shells, 黑云, 萨科塔之眼)
- #11 赫默's drone only from her skill; placeable summons limited to talent tokens
- #12 炎佑 stays where it is with no enemies; 祛恶之焰 as a continuous channel
- #13 the occasional giant bond icon (loading texture scaled ×46) fixed
- docs (DESIGN §18), recordings, data and tests updated (2467 unit tests, all browser suites green)

test/assets.test.js

@@ -319,6 +319,18 @@ describe('audio banks and plan id sets', () => {
     assert.deepEqual(pickUnitSfx(banks), { hit: ['e/hit.mp3'] });
   });
 
+  test('operators: normal-mode sounds only, their own projectile banks as fallbacks (user playtest #4 item 6)', () => {
+    // 纯烬艾雅法拉: the numbered ability variant attack.2 is her S3 impact (_s) — never the normal hit
+    const banks = new Map([['ON_ABILITY_START.attack', ['p/p_atk_x_n.mp3']], ['ON_ABILITY_HIT.attack.2', ['p/p_imp_x_s.mp3']]]);
+    assert.deepEqual(pickUnitSfx(banks, { operator: true, projectile: { hit: ['p/p_imp_x_n.mp3'] } }), { attack: ['p/p_atk_x_n.mp3'], hit: ['p/p_imp_x_n.mp3'] });
+    assert.deepEqual(pickUnitSfx(banks), { attack: ['p/p_atk_x_n.mp3'], hit: ['p/p_imp_x_s.mp3'] }, 'enemies / tokens unchanged');
+    // a skill-mode plain bank (_d / _h / _s) is skipped; the plain ability wins over any numbered variant
+    const b2 = new Map([['ON_ABILITY_START.attack', ['p/p_atk_y_h.mp3']], ['ON_ABILITY_START.attack.0', ['p/p_atk_y_n.mp3']], ['ON_ABILITY_ON.attack', ['p/p_atk_y_n2.mp3']]]);
+    assert.deepEqual(pickUnitSfx(b2, { operator: true }).attack, ['p/p_atk_y_n2.mp3']);
+    assert.deepEqual(pickUnitSfx(new Map([['ON_ABILITY_START.attack.1', ['p/p_atk_z_s.mp3']]]), { operator: true }), {}, 'only skill-mode files: no attack sound');
+    assert.deepEqual(pickUnitSfx(undefined, { operator: true, projectile: { born: ['p/b.mp3'] } }), { attack: ['p/b.mp3'] }, 'no unit banks: the projectile bank');
+  });
+
   test('enemy set covers 07 list, bosses and their summons', () => {
     const assets07 = readJson('docs/research/07-assets.json');
     const ids = new Set(collectEnemyIds({ assets07, enemies05: readJson('docs/research/05-enemies.json'), maps05: readJson('docs/research/05-maps.json'), ops03: readJson('docs/research/03-operators.json') }));